Why two mass attracts each other?

[hansda]

You are going into 4D, mathematics and spacetime-model. All "observable things" happen in 3D. Reality is 3D. 4D is a model. Mathematics in 4D model for predicting 3D events is OK.

So you are denying the existence of time, in other words.

The "time" which you are referring above is "time as indicated by a local clock". This "time" is dependent on clock. This "time" is dependent on gravity as the clock is affected by gravity because mass and energy of a clock can not escape "Gravitational-Field". This "time as indicated by a local clock" can undergo "time dilation".

I am not denying idea of time but we dont have a direct perception of time like distance.

You are contradicting yourself now. If you are not denying the existence of time, and you are not denying the existence of 3D space, then you must accept a 4D universe.
If you are denying time, then you cannot perceive yourself getting older ? What a strange world you live in !

So be clear - do or do you not accept that time exists ?

The "time" which i am referring here is the "real time". This "real time" is independent and uniform for all mass, energy, space and their relative motions. This "real time" moves only in one direction(arrow-of-time) from past to present to future. No clock can hold this "real time". This "real time" is independent of clock or gravity and does not undergo "time dilation".


So, you should understand the difference between the "time as indicated by a local clock" and the "real time".

So, the "time as indicated by a local clock" is not the "real time".

 

[Beer w/Straw]

Metaphysics?

 

[hansda]

I am not sure if the OP question was answered, but in case it is still open to input,

It is still open.

IMO, two massive objects, or three, or one hundred, do not attract or repel each other by potential differences, such as polarity. They always 'appear' to attract each other.

Why there is no possibility of "appear to repel"?

I see this as a (potential) function of spacetime itself, caused by the presence of a massive object. Each massive object creates a spacetime distortion, a kind of "dimple" in the fabric of space which allows other objects to fall into the "dimple", toward the massive object. Thus no matter how many massive objects there are, each creates it's own dimple in spacetime and together they make one giant dimple and all objects within reach fall toward the center of the largest dimples and ultimately to the center (the sum of mass) of all spacetime dimples. I think black holes are extreme examples of such spacetime distortions.

Perhaps this is an expression of Gravity, where the "center of gravity" is always at the center of the spacetime dimple, the most massive part of a massive system.

I am confident we can say "spacetime dimple" because, as I understand it, the passage of time itself is also affected in the proximity of a massive object. I don't see how the two can be separated and IMO, each tends to confirm the other, don't ask me how......

Lorentz-Force is due interaction of Electrical-Field and Magnetic-Field. Lorentz-Force can also move a massive object. Is Lorentz-Force due to "spacetime-distortion(or dimple)?



I think there may be some connection between "Gravity" and "Lorentz-Force".

 

[hansda]

Metaphysics?

"Real Time" always keeps us in the "present". "Time Reversal" is not yet proven, not in the particle level also.

 

[eram]

Farsight is such a bewitching character -people like him actually exist! I guess being watchfully amused is probably the best way to learn of these non-fictitious beings.

Farsight does have a few screws loose , but I'm pretty sure he's not alone.

I believe that Farsight's delusion around this particular point is based, like many, on the fact that he really has never studied physics. He only does a textual analysis of abstracts and the introductory sections of Einstein's chapters... I suspect that he once tried and realized that he couldn't do it without invoking time and so, dishonestly, he stopped trying to answer the question.

In geek speak, Farsight just doesn't have enough processor speed. About time he realized his limitations.



@Markus, first Farsight. now hansda.

hansda's a little senile though. In this thread, he had great difficulty understanding Newton's cradle, Newton's third law and even basic energy transfer.

http://www.sciforums.com/showthread.php?133680-Speed-of-Force-or-Transfer-of-Momentum

 

[Beer w/Straw]

"Real Time" always keeps us in the "present". "Time Reversal" is not yet proven, not in the particle level also.

That has to be the crappiest strawman -my sentence consisted of one word!

 

[eram]

That has to be the crappiest strawman -my sentence consisted of one word!

He's probably got dementia so god knows what's going on inside his mind.

 

[Write4U]

hansda

Write4U,

IMO, two massive objects, or three, or one hundred, do not attract or repel each other by potential differences, such as polarity. They always 'appear' to attract each other.

Why there is no possibility of "appear to repel"?

Because gravity is the only force that is effective at great distances.

Properties of the Fundamental Forces
•The strong interaction is very strong, but very short-ranged. It acts only over ranges of order 10-13 centimeters and is responsible for holding the nuclei of atoms together. It is basically attractive, but can be effectively repulsive in some circumstances.

• The electromagnetic force causes electric and magnetic effects such as the repulsion between like electrical charges or the interaction of bar magnets. It is long-ranged, but much weaker than the strong force. It can be attractive or repulsive, and acts only between pieces of matter carrying electrical charge.

• The weak force is responsible for radioactive decay and neutrino interactions. It has a very short range and, as its name indicates, it is very weak.

• The gravitational force is weak, but very long ranged. Furthermore, it is always attractive, and acts between any two pieces of matter in the Universe since mass is its source.

http://csep10.phys.utk.edu/astr162/lect/cosmology/forces.html

I see this as a (potential) function of spacetime itself, caused by the presence of a massive object. Each massive object creates a spacetime distortion, a kind of "dimple" in the fabric of space which allows other objects to fall into the "dimple", toward the massive object. Thus no matter how many massive objects there are, each creates it's own dimple in spacetime and together they make one giant dimple and all objects within reach fall toward the center of the largest dimples and ultimately to the center (the sum of mass) of all spacetime dimples. I think black holes are extreme examples of such spacetime distortions.

Perhaps this is an expression of Gravity, where the "center of gravity" is always at the center of the spacetime dimple, the most massive part of a massive system.

I am confident we can say "spacetime dimple" because, as I understand it, the passage of time itself is also affected in the proximity of a massive object. I don't see how the two can be separated and IMO, each tends to confirm the other, don't ask me how

Lorentz-Force is due interaction of Electrical-Field and Magnetic-Field. Lorentz-Force can also move a massive object. Is Lorentz-Force due to "spacetime-distortion(or dimple)?

I identified the other three forces as being caused by differences in potential, i.e. polarity.

I think there may be some connection between "Gravity" and "Lorentz-Force".

IMHO, perhaps the Lorentz force is indirectly connected to Gravity in that it deals with momentum and kinetic force of massive objects, each of which has a gravitational field of course. Interestingly, the below quote seems to confirm my statement that the center of gravity is always located at the greatest concentration of combined masses. In the case of a BH this point is a singularity, in the case of galaxies the center of gravity may not lie inside an object at all, but at the center of the system itself.

What role exactly does m(v) play in dynamics? The only physical purpose of mass is to establish a
relationship between dynamics (forces) and kinematics (motion) of bodies, and our real goal here is to
discover how relativistic objects respond to forces.. In order to answer this question we must recognize that dynamics implicitly enters the discussion above through the center-of-mass. For two bodies with
momenta p1 and p2 (in some reference frame) and masses m1 and m2 respectively, the center of mass
is a fictitious point which carries the total momentum P = p1 + p2 the way a particle with the total
mass M = m1 + m2 would, that is with velocity u = P=M.

http://physics.gmu.edu/~pnikolic/PHYS308/lectures/relativity2.pdf

 

[PhysBang]

In geek speak, Farsight just doesn't have enough processor speed. About time he realized his limitations.

More appropriate would be to say that he's trying to edit a picture with photoshop, but he only has the Windows bitmap editor.

 

[ash64449]

The "time" which you are referring above is "time as indicated by a local clock". This "time" is dependent on clock. This "time" is dependent on gravity as the clock is affected by gravity because mass and energy of a clock can not escape "Gravitational-Field". This "time as indicated by a local clock" can undergo "time dilation".





The "time" which i am referring here is the "real time". This "real time" is independent and uniform for all mass, energy, space and their relative motions. This "real time" moves only in one direction(arrow-of-time) from past to present to future. No clock can hold this "real time". This "real time" is independent of clock or gravity and does not undergo "time dilation".


So, you should understand the difference between the "time as indicated by a local clock" and the "real time".

So, the "time as indicated by a local clock" is not the "real time".

what is 'time' then? Can you explain what 'real time' is? How you define this 'real time'?

 

[ash64449]

wait...
Why two masses attract each other?
Its all in equivalance principle!!

 

[hansda]

wait...
Why two masses attract each other?
Its all in equivalance principle!!

How? Can you prove?

"Two mass attract each other." - This is an observable fact. You should be able to explain, "why"?

 

[hansda]

what is 'time' then? Can you explain what 'real time' is? How you define this 'real time'?

"Time Reversal" is not yet experimentally proved. "Time Reversal Violation" has been experimentally proved."Time Dilation" is also proved with a clock.


So, it can be said that "time as indicated by a clock" dilates but "flow of time" which follows 'arrow of time' does not 'reverse back', 'slow down' or 'dilate'.


This "flow of time" can be considered as the 'real time'.

 

[ash64449]

How? Can you prove?

"Two mass attract each other." - This is an observable fact. You should be able to explain, "why"?

find it out yourself

 

[ash64449]

"Time Reversal" is not yet experimentally proved. "Time Reversal Violation" has been experimentally proved."Time Dilation" is also proved with a clock.


So, it can be said that "time as indicated by a clock" dilates but "flow of time" which follows 'arrow of time' does not 'reverse back', 'slow down' or 'dilate'.


This "flow of time" can be considered as the 'real time'.

you do not understand what you are saying!! Ur words don't make sense because you haven't define what 'time' is.
So what is 'time'? And you are saying there are two types of time:'real' time and proper time and coordinate time. So here are different types of time. But what is 'time'? Got the point? From that definition (your own) of 'time',distinguish 'real' time and other time.

 

[hansda]

Because gravity is the only force that is effective at great distances.

"Distance" determines the strength of a "force" but not its direction. "Force" also can be 'repulsive at a distance', as in the case of Electrical charges or magnets.

 

[hansda]

you do not understand what you are saying!! Ur words don't make sense because you haven't define what 'time' is.
So what is 'time'? And you are saying there are two types of time:'real' time and proper time and coordinate time. So here are different types of time. But what is 'time'? Got the point? From that definition (your own) of 'time',distinguish 'real' time and other time.

"Time" is the non-spatial interval between two events. "Real Time" is the natural flow of this time. "Real Time" is uniform, independent of gravity and follows 'arrow of time'.

"Time indicated by a clock" is not "Real Time". "Time indicated by a clock" is non-uniform, 'dependent on gravity' and 'undergoes time-dilation'.



For example if a clock can be kept at Black-Hole, this clock will show 'no passage of time' but 'arrow of time' is present there. "Real Time" is present in the Black-Hole but "time as indicated by a clock" is not present in the Black-Hole.

 

[OnlyMe]

"Time Reversal" is not yet experimentally proved. "Time Reversal Violation" has been experimentally proved."Time Dilation" is also proved with a clock.


So, it can be said that "time as indicated by a clock" dilates but "flow of time" which follows 'arrow of time' does not 'reverse back', 'slow down' or 'dilate'.


This "flow of time" can be considered as the 'real time'.

Hansda, time is an abstract label we use to define the rate that change occurs at. Change does occur even when we are not observing or measuring it, but time requires that "we" make some rate of change comparison, with a predetermined standard rate. In some ways you could say that choosing a standard rate of change is arbitrary. It has changed over the corse of history, as we have discovered more accurate mechanisms, to reference as a standard.

Change is real and is not observer dependent. The rate of change or what we call "time" is observer dependent. It depends on from where we observe events or change and what mechanism we use to define a standard rate. There is no universal time or rate of change, because we are limited to observing and measuring change, the rate of change, or time.., from where and when we are located. We can project how the rate of change would be affected by changes in location and velocity, but even then we are only labeling the rate of change for another unique frame of reference, not any universal frame.

 

[quantum_wave]

"Time" is the non-spatial interval between two events. "Real Time" is the natural flow of this time. "Real Time" is uniform, independent of gravity and follows 'arrow of time'.

"Time indicated by a clock" is not "Real Time". "Time indicated by a clock" is non-uniform, 'dependent on gravity' and 'undergoes time-dilation'.



For example if a clock can be kept at Black-Hole, this clock will show 'no passage of time' but 'arrow of time' is present there. "Real Time" is present in the Black-Hole but "time as indicated by a clock" is not present in the Black-Hole.

I couldn't agree more. Time simply passes. The measurement of time is variable based on the energy density of the environment.

As Markus says elsewhere, "Space-time Geometry = Energy Content"

"And this is exactly what GR is all about; gravity is not described in terms of forces, but as a geometric property of space-time itself. Space-time curvature and energy content are one and the same thing; we can interpret this as energy "curving" space-time, or equivalently as curvature manifesting itself as energy, e.g. mass."

 

[OnlyMe]

"And this is exactly what GR is all about; gravity is not described in terms of forces, but as a geometric property of space-time itself

GR does not describe "gravity".., it describes the "affects" of gravity.